Title :
Phase contrast method for measuring ultrasonic fields
Author :
Reichel, Erwin K. ; Zagar, Bernhard G.
Author_Institution :
Inst. for Meas. Technol., Johannes Kepler Univ. Linz, Austria
Abstract :
Pulsed acoustic waves in water generated by ultrasonic transducers with power levels in the medical diagnostic range are characterized by analyzing the optical diffraction patterns of short laser pulses due to the pressure waves to be analyzed. The diffracted laser light is filtered in the Fourier plane of an optical system and projected onto a charge-coupled-device camera to be grabbed and further processed. Using this technique, it is possible to measure and characterize the ultrasound field in minutes time, which would otherwise last hours or days using the standard method of measuring the intensity on a fine three-dimensional grid with a hydrophone. In addition, the phase information of the ultrasonic wave is acquired easily.
Keywords :
acoustic field; acoustic intensity measurement; biomedical transducers; patient diagnosis; ultrasonic transducers; Fourier optics; Fourier plane; acoustooptic measurement; charge-coupled-device camera; hydrophone; laser light; laser pulses; medical diagnostic; optical diffraction patterns; optical system; phase contrast method; pulsed acoustic waves; schlieren technique; ultrasonic fields measurement; ultrasonic transducers; ultrasonic wave; Acoustic measurements; Acoustic pulses; Acoustic waves; Optical diffraction; Optical filters; Optical pulse generation; Pattern analysis; Phase measurement; Time measurement; Ultrasonic variables measurement; Acoustooptic measurement; Fourier optics; phase contrast method; schlieren technique; ultrasonic transducers;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
DOI :
10.1109/TIM.2006.876397
